The Great Maintenance Update. No new features here. Instead, we've updated the build system to webpack 4, updated all our dependencies, and cleaned up a lot of linting issues.
* Added: Highlight messages based on usernames and badges.
* Added: Block messages based on usernames and badges.
* Fixed: Display the number of months a subscriber has subscribed in badge tool-tips.
* Fixed: Rendering of chat messages sent from Twitch Extensions.
* Added: Remove messages entirely using Blocked Terms.
* Fixed: Position of emotes in locally echoed chat messages containing emoji.
Added a `chat:receive-message` event for processing incoming chat messages before they're added to the buffer.
* Update all usages of `tw-input` and `tw-select` to use the new, overly-verbose classes Twitch added.
* Add a few of the monkey faces to the local emote code to make them work.
* Override emotes when building the emote code <-> id map, to let emotes from higher sets override global emotes.
